diff --git a/src/cmd/compile/internal/gc/const.go b/src/cmd/compile/internal/gc/const.go
index 0a00825b856..d30515a87b6 100644
--- a/src/cmd/compile/internal/gc/const.go
+++ b/src/cmd/compile/internal/gc/const.go
@@ -664,7 +664,8 @@ func evconst(n *Node) {
 		case OCONV_ | CTINT_,
 			OCONV_ | CTRUNE_,
 			OCONV_ | CTFLT_,
-			OCONV_ | CTSTR_:
+			OCONV_ | CTSTR_,
+			OCONV_ | CTBOOL_:
 			convlit1(&nl, n.Type, true)
 
 			v = nl.Val()
diff --git a/src/cmd/compile/internal/gc/typecheck.go b/src/cmd/compile/internal/gc/typecheck.go
index 70560d405df..224480279c8 100644
--- a/src/cmd/compile/internal/gc/typecheck.go
+++ b/src/cmd/compile/internal/gc/typecheck.go
@@ -688,17 +688,7 @@ OpSwitch:
 				n.Right = r
 			}
 		} else if n.Op == OANDAND || n.Op == OOROR {
-			if l.Type == r.Type {
-				t = l.Type
-			} else if l.Type == idealbool {
-				t = r.Type
-			} else if r.Type == idealbool {
-				t = l.Type
-			}
-		} else
-		// non-comparison operators on ideal bools should make them lose their ideal-ness
-		if t == idealbool {
-			t = Types[TBOOL]
+			evconst(n)
 		}
 
 		if et == TSTRING {
@@ -1751,7 +1741,7 @@ OpSwitch:
 
 		switch n.Op {
 		case OCONVNOP:
-			if n.Left.Op == OLITERAL && n.Type != Types[TBOOL] {
+			if n.Left.Op == OLITERAL {
 				r := Nod(OXXX, nil, nil)
 				n.Op = OCONV
 				n.Orig = r
diff --git a/test/fixedbugs/issue13821.go b/test/fixedbugs/issue13821.go
new file mode 100644
index 00000000000..7d5024893f9
--- /dev/null
+++ b/test/fixedbugs/issue13821.go
@@ -0,0 +1,15 @@
+// compile
+
+// Copyright 2015 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Issue 13821.  Compiler rejected "bool(true)" as not a constant.
+
+package p
+
+const (
+	A = true
+	B = bool(A)
+	C = bool(true)
+)
diff --git a/test/fixedbugs/issue13821b.go b/test/fixedbugs/issue13821b.go
new file mode 100644
index 00000000000..3b0e2d2287e
--- /dev/null
+++ b/test/fixedbugs/issue13821b.go
@@ -0,0 +1,22 @@
+// errorcheck
+
+// Copyright 2015 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Issue 13821.  Additional regress tests.
+
+package p
+
+type B bool
+type B2 bool
+
+var b B
+var b2 B2
+var x1 = b && 1 < 2 // x1 has type B, not ideal bool
+var x2 = 1 < 2 && b // x2 has type B, not ideal bool
+var x3 = b && b2    // ERROR "mismatched types B and B2"
+var x4 = x1 && b2   // ERROR "mismatched types B and B2"
+var x5 = x2 && b2   // ERROR "mismatched types B and B2"
+var x6 = b2 && x1   // ERROR "mismatched types B2 and B"
+var x7 = b2 && x2   // ERROR "mismatched types B2 and B"